Heart Function Recovers Quickly in Children With COVID-19-Related MIS-C

January 19, 2022

Heart function recovery returned within 3 months in children who developed coronavirus disease 2019 (COVID-19)-related multisystem inflammatory syndrome (MIS-C), according to a study published in the Journal of the American Heart Association Report.

This study details the cardiovascular complications or damage found during a 3-month follow-up period to assess the short-term impact of MIS-C. It also employs newer cardiac measurements, known as “strains,” to assess heart function related to MIS-C. Strain testing is a more sensitive tool that can detect whether an area of the heart is deformed or if there are any subtle changes in heart function during cardiac contraction and relaxation.

“There is limited data at this time about how frequently and how long we should monitor heart function during the recovery state of MIS-C after the child leaves the hospital,” said Anirban Banerjee, MD, University of Pennsylvania Perelman School of Medicine, Philadelphia, Philadelphia. “Given that MIS-C was identified as a result of the COVID-19 pandemic, treatment protocols have not yet been standardised and follow-up care varies greatly, which may lead to confusion and anxiety among families of patients and their care team. Our research team hoped to provide some guidance and reduce the ambiguity on optimal care approaches, especially as it relates to sports participation.”

The researchers retroactively reviewed data on 60 children (average age, 10 years) hospitalised with MIS-C due to COVID-19 exposure who were treated at 2 Philadelphia hospitals between April 2020 and January 2021. All patients were treated with intravenous immunoglobulin and/or systemic steroids. Researchers reviewed echocardiographic and clinical data from medical records, including demographic factors, testing, treatment, and hospital outcomes.

Data on another 60 children who had structurally normal hearts and did not have MIS-C or COVID-19 exposure served as control subjects. The control participants were divided into 2 groups: 60% had echocardiograms on file that were done prior to the COVID-19 pandemic, and 40% had echocardiograms under rigid COVID-19 protocols after October 2020.

For the children with MIS-C, researchers analysed images of the heart taken at the initial hospitalisation (acute phase) and examined additional imaging for a portion of the children who also had scans up to three additional times -- 1 week after the first scan (subacute phase); at the 1-month follow-up; and at a 3- or 4-month follow-up. The children were screened using conventional echocardiography, speckle tracking echocardiography, and  cardiac MRI.

Based on echocardiogram imaging, systolic and diastolic function in the left ventricle and systolic function in the right ventricle improved quickly within the first week, followed by continued improvement and complete normalisation by 3 months. Of the patients, 81% lost some contractile function in the left ventricle during the acute phase of illness, yet, by months 3 and 4, contraction function had returned to normal.

MIS-C did not cause lasting coronary artery abnormalities. During the initial hospitalisation, 7% of patients had evidence of some heart malfunction; however, all scans were normal by the 3-month follow-up.

Using strain parameters to measure cardiac function, the results suggest that there is no subclinical cardiac dysfunction after 3 months.

“Recovery among these children was excellent,” said Dr. Banerjee. “These results have important implications for our healthcare teams managing care for children with MIS-C. Our findings may also provide guidance for a gradual return to playing sports after cardiac clearance 3 to 4 months later. Tests needed for clearance include electrocardiogram and echocardiogram. We also recommend cardiac MRI for children who have highly abnormal baseline cardiac MRI during the acute stage or show evidence of continued severe left ventricle dysfunction.”

The study researchers note there are still important gaps in existing knowledge about MIS-C, since COVID-19 and MIS-C are both new illnesses. The most important question yet to answer is how these children are faring 1 to 2 years after their initial hospitalisation.

Reference: https://www.ahajournals.org/doi/10.1161/JAHA.121.023251

SOURCE: American Heart Association